mccormick



UNITED STATES PATENT OFFICE.

WM. S. MCCORMIOK, OF CHICAGO, ILL., ASSIGNOI-t lO CYR US II. MCCORMICK.

IMPROVEMENT l N`CUTTERS FOR REAPlNG AND MOWlNG MACHINES.

Specilication forming part ofLetters Patent No. 33,681, dated November 5, 1561 'To all 'whom 'it may concern:

Be it lknown that I, WILLIAM S; MCCOR- MIGK, of Chicago, in the county of Cook and State of Illinois, have invented certain new and nsefullmprovements in. Cutters for Mowin g-Machines and Keeping-Machines, of which the following is a. full, clear, and exact description,reference being had to the accompanying drawings, which make part ofthisspccitication, and in which-- Figure 1 represents a view in perspective of a portion of a cutter embracing my improvements. Fig. 2 represents a similar view of the under side ofthe same. Fig. 3 represents an eleva-tion of the rear of the saine, and Fig. et represents a section at the line a: x oI" Fig. 1.

[t isdesirable to make a cutter for. mowing and reaping as light as is' consistent with a due degree of strength,`becaus'e from the rapid niotion at which the cutter is vibrated a. great waste of power' is involved in moving any superljuous weight. In addition, however, to the requisite strength, the cutter must havefbearing-surfaces of adequate Width to prevent abrasion, to slide in contact with the guides, vwhich keep it in place While at Work. I have found that by making the blade ofthe cutter narrow and the indentations shallow and working it in the McCormick slotted finger, in which the back angles hold the stalks from yielding forward to the pressure ot' the edge `of the blade while cutting, I can use a. very thin and light bar to rivet the blade to; but such a bar has not the requisite stiffness to support it properly against the end-thrust and backward pressure while cutting. To avoid this dii'I'icultv without increasing too much the -V weight of the bar, I make the bar even still thinner than heretofore, and then give it stili?- ness and, when necessary', more rear bearingsurface by making a. vertical rib or flange on one or both of its sides behind theblade, and extending the bar in rear of the vertical liange far enough to form a horizontal lange, aud arranging one or more of these flanges totslide against the bearings ofthe guides, and notch one or more of the flanges of the cutter-bar- Ato make them take hold more 'readily of obstructing matter and detach and discharge it from the `guide in which they slide. The notches in the opposite flan ges may be inclined in opposite directions, so that the oppositelyinclined series ot' notches may push alter-A nately, andv thus maintain with an intermittent action, as near as may be, an equable resistance to the cutter While it is performing the cleaning` function.

The bar A, to which the blade B is riveted, may be made ot' a single piece of metal, forged or rolled or cast into the proper shape; or it may be a composite bar, consisting of three pieces-a broad bar, with two vertical `ianges or ribs, a ai', made separately,and then either riveted, screwed, brazed, or otherwise secured to the sides ofthe bar.

f The blade B is riveted to the front part, a, of the bar. The rear purga, ofthe bar, back of thetop and bottom ribs, forms a horizontal flange to give additional horizontal stiffness and strength to the blade; andthe rear side ot' this part may bear against the guides in which the cutter slides.

The part a. should be pierced with a. series of holes for the rivets which `fasten the blade.

These'holes I prefer to make by drilling; but

they may be made by punching.

. The notches b in the iianges may be made ot' any convenient form; but I pret'er to make them like aseries of ratchet-teeth.

If the cutter-bar and its ianges should be* -backot' the bar, may be made to bear against guides -arran ged for the purpose.- Such a guide may be formed in the finger-beam, in the slot of the fingers, or in brackets attached lfor the purpose to the linger-beam; or the guide may be partly in two or in all three of them,as the structnreof the tnger-bealn or fingers, or other circumstances may render expedient.

The blade may be made in one piece of steel or in sections. l prefer the latter.

WhatI claim as my invention, and desire to secure by Letters Patent, is

The anged cutter-bar with notches in one or more of the flanges, substantially as described. v

In witness Whereot I have hereunto sub- 'scribedmyname XVM. S. MGOORMICK.

Witnesses:

J AMES T. SNIFFIN, GEORGE W. Evaars. 

